England coach Stuart Lancaster has been handed a host of injury concerns ahead of the Six Nations following a bruising weekend of European action.

Lancaster's squad is due to gather in Leeds tonight for a training camp ahead of their opener with Scotland at Twickenham on February 2 but there may be a few absentees who were casualties of the final round of pool action in the Heineken Cup and the Amlin Challenge Cup.

Exeter Chiefs flanker Tom Johnson looks set for the longest lay-off after being stretchered from the field during his side's Heineken Cup defeat to Leinster on Saturday. "He's done something to his knee and his ankle," Chiefs head coach Rob Baxter told BBC Radio Devon. "Until we get it scanned we're not going to know how serious it is."

Northampton boss Jim Mallinder confirmed: "The medics will take a good look at Calum's shoulder but it does not look good and I think he could be out for a while." However, there was better news for lock Courtney Lawes who was forced out of the game following a bang to the head with Mallinder dismissing the blow as nothing serious.

Elsewhere, Gloucester fly-half Freddie Burns, who made his debut in England's victory over New Zealand last month, picked up a knee injury in his side's Challenge Cup victory over French side Mont-de-Marsan at Kingsholm

"He's tweaked his medial ligament in his knee and we'll have to wait and see how bad it is," Gloucester director of rugby Nigel Davies told BBC Radio Gloucestershire. "We'll get a better feeling for it over the next 48 hours once some of the swelling goes down and we get it scanned, but it is a little bit unfortunate for Freddie," Davies told BBC Radio Gloucestershire.

Worcester flanker Matt Kvesic, Saracens lock Mouritz Botha and Harlequins winger Ugo Monye have all been called up into the training squad from the Saxons as a result. London Irish's Jamie Gibson replaces Kvesic in the Saxons squad for their games against Ireland Wolfhounds in Galway on Friday, January 25 and Scotland A at Kingston Park, Newcastle seven days later.